1. Field of the Invention
The present invention relates to new aqueous dispersions of polyester-polyurethanes, their use as binder components in coating compositions and soft feel coatings prepared from these coating compositions.
2. Description of the Prior Art
Current aqueous binders can replace binders dissolved in organic solvents in many applications. This applies above all to areas, such as electrophoretic enamelling, wherein aqueous binders can have definite advantages.
For applications having very special requirements, such as the enamelling or coating of plastics using soft feel coatings, the presently available aqueous binders have not been able to meet the necessary requirements.
The properties provided by organic solvent-based polyurethane soft feel coatings (for example, PCT Application WO 92 15 636 or Japanese Patent Application 279 620 dated Nov. 11, 1986 having the publication number J63132-919-A), particularly as regards the soft feel effect, the resistance to solvents, the film mechanics and the bonding to the substrate, has not yet been achieved by aqueous systems. In particular, a coating possessing a good soft feel effect combined with a satisfactory resistance to solvents has not been possible using aqueous products.
An object of the present invention is to provide aqueous binders which are suitable for use in flexible lacquer, coating and sealing compositions, in particular for the production of soft feel coatings, and which combine a good soft feel effect, good film mechanics and surface bonding, and acceptable resistance to solvents. It is an additional object of the present invention for these compositions to contain as few volatile organic substances as possible, so that they are capable of satisfying environmental requirements.
These objects may be achieved with the aqueous polyester-polyurethane dispersions and coating compositions described in more detail below.